Variable speed drive for bicycles and the like

Abstract

A variable speed "stiff-hub " drive adapted particularly to bicycles and comprised of a constant mesh infinitely variable gearing with an integral input crank shaft projecting axially from opposite ends of an enclosing case, with a drive sprocket at one side of the case and coaxially disposed over one of said crank shaft ends, and having a control means which operates in conjunction with a single lever which also comprises the braking force actuator.

I claim: 
     
       1. A low velocity high torque infinitely variable speed constant mesh transmission for bicycles and the like, including; a case with a crank shaft extending therethrough and with its opposite ends projecting from the case, a first stage speed changer comprising, a stationary ring gear and an input planet gear journaled on a carrier driven by the crank shaft and in constant mesh with said ring gear, and an output sun gear in constant mesh with said planet gear to be driven at increased angular velocity thereby; and a second stage speed changer comprising, an input sun gear driven by the first stage sun gear and a planet gear journaled on an output carrier rotatable over the crank shaft and in constant mesh with said second stage sun gear, and a rotatable ring gear in constant mesh with said planet gear; and an infinitely variable speed feedback drive means driven by the output carrier of the second stage and controlling the angular velocity of the rotatable second stage ring gear to effect a commensurate velocity change between the crank shaft and the output carrier. 
     
     
       2. The two-stage infinitely variable speed constant mesh transmission as set forth in claim 1 wherein the feedback drive means is a non-reversible gear engagement with the second stage ring gear. 
     
     
       3. The two-stage infinitely variable speed constant mesh transmission as set forth in claim 1, wherein the infinitely variable feedback is a high velocity drive rotating the second stage ring gear to reduce velocity in said second stage speed changer. 
     
     
       4. The two-stage infinitely variable speed constant mesh transmission as set forth in claim 1, wherein the infinitely variable feedback comprises inversely tapered cones with an axially positioned belt engaged therebetween, one cone driven by the output carrier of the second stage speed changer and the other cone driving the rotatable ring gear of the second stage speed changer. 
     
     
       5. The two-stage infinitely variable speed constant mesh transmission as set forth in claim 1, wherein the infinitely variable feedback comprises inversely tapered cones with an axially positioned belt engaged therebetween, one cone driven by the output carrier of the second stage speed changer and the other cone driving the rotatable ring gear of the second stage speed changer through a non-reversible worm and wheel drive. 
     
     
       6. The two-stage infinitely variable speed constant mesh transmission as set forth in claim 1, wherein the case has spaced end walls with carrier bearings through which the crank shaft projects with oppositely exposed ends. 
     
     
       7. The two-stage infinitely variable speed constant mesh transmission as set forth in claim 1, wherein the case has spaced end walls with carrier bearings through which the crank shaft and second stage carrier extend outside the case with the opposite ends of the crank shaft driveably exposed. 
     
     
       8. The two-stage infinitely variable speed constant mesh transmission as set forth in claim 1, wherein the case has spaced end walls with carrier bearings through which the crank shaft and second stage carrier extend outside the case with a drive sprocket exposed on the carrier and with opposite ends of the crank shaft driveably exposed. 
     
     
       9. The two-stage infinitely variable speed constant mesh transmission as set forth in claim 1, wherein the infinitely variable feed comprises a right angle gear driven from the second stage carrier and on an axis parallel to feed back gearing into the second stage ring gear. 
     
     
       10. The two-stage infinitely variable speed constant mesh transmission as set forth in claim 1, wherein the infinitely variable feedback comprises inversely tapered cones journaled on spaced parallel axes disposed normal to the crank shaft axis, an axially positioned belt engaged between the cones, one cone driven by the output carrier of the second stage speed changer and the other cone driving the rotatable ring gear of the second stage speed changer. 
     
     
       11. The two-stage infinitely variable speed constant mesh transmission as set forth in claim 1, wherein the infinitely variable feedback comprises inversely tapered cones journaled on spaced parallel axes disposed normal to the crank shaft axis, an axially positioned belt engaged between the cones, one cone driven by the output carrier of the second stage speed changer and the other cone driving the rotatable ring gear of the second stage speed changer through a non-reversible worm and wheel drive.